1. Field of the Invention
The present invention relates to a method for forming a curved surface in a decorated board which is used as an ornamental panel for furniture such as a headboard of a bed, a backrest or an armrest of a chair, as well as an architectural product such as a door panel or a partition plate between rooms.
2. Description of the Related Art
Conventionally, a variety of furniture products have been easily formed to have a curved surface, using a mold in the event that they are made of synthetic resin or metal. For woody furniture products, however, they are produced by working flat plate materials in general, and thus if a curved surface is employed as a part of design for a certain furniture product, then a flat plate material which was cut to a predetermined size beforehand must be bent, using a pressing machine or the like.
For a headboard for bed, for example, a peripheral edge of a material sometimes undergoes a woodworking process so as to chamfer the corners thereof, and/or the surface of a headboard might be formed with a decorative irregular pattern to enhance the attractiveness of design. These woodworking or decorative patterning to the surface of a headboard has heretofore been carried out by a machining device, and painting has been applied to headboards thus worked or decorated to a final product.
However, when a headboard is designed to eventually define a curved surface as a whole, and that in the event that a planar wood material is first bent and then a peripheral edge thereof undergoes woodworking or surface decorating, then it would be necessary to control a machining device and/or a painting nozzle three-dimensionally, to adjust to the curvature of the bent wooden material. Particularly for woodworking of the peripheral edge of a wooden material, a woodworking device must be operated along the outline thereof, and be controlled to comply with the curvature of the plate material. If these steps are automated, using a machining device, then extremely complicated control must be performed, which is only possible by using an extremely expensive five-axis control device.
Therefore, in a case where woody furniture products such as headboards employ a curve design, most of them have heretofore been produced by simply bending a flat board, without going through any woodworking process. In other words, as wood-based materials include moisture contents that vary widely in general, and are stored in varying conditions, and that temperature and moisture at the time of woodworking are hardly kept constant, it has been very difficult to keep a bending angle constant. Besides, post-bending process is extremely difficult due to the occurrence of backlash. Although simple rounding work which permits roughness to some extent is possible, precise working with precise accuracy is very difficult.
The present invention address the above-mentioned problems, with the object of providing a method for forming a curved surface in a decorated board which enables a variety of finish processing to be performed on a decorated board without using an expensive five-axis control device, while enhancing a degree of freedom in design.
To attain the above objects, there is provided, according to a first aspect of the invention, a method for forming a curved surface in a decorated board formed by laminating a flat decorating material to a flat woody base board, which comprises the steps of: working at least one of the said base board and the decorating material; laminating said decorating material to said base board to integrally form a decorated board; and subjecting said decorated board to a bending process to define a curved surface.
With the construction of the first aspect, a woodworking process is performed with the base board and/or the decorating material remaining flat, which undergo a painting process where necessary, and then they are subjected to a bending process. Accordingly, when subjecting the peripheral edges of the base board and the decorating material to the woodworking process, using a machining device, it suffices to control the device so that it may run along the peripheral edge of the flat base board and decorating material, and thus, no complicated five-axis control is necessary, thereby leading to an enhanced production processability. The base board and decorating material thus curved have their peripheral edges formed with decorating patterns or outlines, as a result of the woodworking.
According to a second aspect of the present invention, there is provided a method for forming a curved surface in a decorated board as set forth in the first aspect, wherein a positioning means for positioning said base board and said decorating material is provided when they are laminated to each other.
Accordingly, when bending the decorated board after integrally laminating the decorating material to the base board, the decorating material can be precisely fixed to the base board, without causing misalignment or displacement therebetween.
According to a further aspect of the present invention, there is provided a method for forming a curved surface in a decorated board formed by laminating two flat base boards, which comprises the steps of: forming a step groove in at least an inner edge of each base board; laminating these two base boards each other to integrally form a decorated board; subjecting the decorated board to a bending process; covering the bent decorated board with a cloth, while accommodating a margin of the cloth into a concave groove formed by said step groove of each base board.
In the case of covering the decorated board with a cloth, two cloth pieces are sewed up together to form a sack for covering the same. At this moment, a cloth margin is formed in the rear face side of the sack. As this cloth margin is accommodated into the concave groove formed by the step grooves, the surface of the cover cloth is free from irregular wrinkles, resulting in presentable appearance. Further, as the concave groves for accommodating the cloth margin are formed, with the respective base boards remaining flat, no three-dimensional control for running along the respective curves of the boards, is necessary, thus leading to an enhanced production processablity.